1. Field of the Invention
The present invention relates to an auger type ice making machine, and more particularly to a protective device for the ice making machine for preventing the ice discharge passage of the ice making machine from being blocked with ice pieces supplied therein.
2. Description of the Prior Art
In a conventional auger type ice making machine the refrigeration housing of which is located adjacent an ice storage bin and provided thereon with an ice discharge casing forming a lateral discharge passage for discharging ice pieces into the ice storage bin therefrom through an upright delivery chute, an ice detection device is provided within the delivery chute at a position adjacent an outlet of the lateral discharge passage. In operation of the ice making machine, ice pieces are supplied into the lateral discharge passage from the refrigeration housing and fall into the ice storage bin through the delivery chute. When the delivery chute is filled with the ice pieces due to increase of the amount of ice pieces stored in the storage bin, a movable detection plate of the ice detection device is moved by the ice pieces to deactivate the ice making mechanism. If the ice detection device was not operated due to unexpected trouble, the lateral discharge passage of the casing would be blocked with ice pieces continuously supplied from the ice making mechanism. This results in an increase of the internal pressure of the ice discharge casing and an increase of load acting on a geared-motor of the ice making mechanism. If the geared-motor is locked by increase of the load acting thereon, a protective device for prevention of excessive current is operated to deactivate the ice making machine. In the ice making machine, it is, however, afraid that the internal pressure of the ice discharge passage excessively increases before the geared-motor is deactivated by operation of the protective device, resulting in damage of the ice discharge casing.
In an auger type ice making machine disclosed in Japanese Patent Laid-open Publication No. 3-25190, an ice guide member is mounted on an extended portion of a refrigeration housing and loaded by a spring downwardly to introduce ice pieces into a lateral discharge passage. When the ice guide member is raised by increase of the internal pressure in the lateral discharge passage, a microswitch is operated by upward movement of the guide member to deactivate the ice making machine. In this ice making machine, the ice guide member is raised by ice pieces supplied at a time into the discharge passage if the ice making performance excessively increases due to fall of the ambient temperature or the water temperature or if ice pieces are packed in the refrigeration housing. This results in unexpected stopping of the ice making machine.